Field of the Invention
Throughout the world, oil producing countries face a common problem which is indigenous to the removal of petroleum products from subsurface deposits. That problem asserts itself in the form of leaky stuffing boxes which result in petroleum spills in the area immediately surrounding the wellhead.
Most, if not all, subsurface wells have certain common elements, among them, a sucker rod, or, indeed, a string of sucker rods, ascending from a polish rod of a pumping apparatus, whether it be walking beam or of the long stroke variety, into the well. A pump, which may take various forms, is disposed at the end of the string, which is in the petroleum deposit. At the wellhead, just above ground level, is a stuffing box through which the polish rod passes.
The stuffing box does precisely what its name suggests, i.e., it holds a packing which is intended to wipe the polish rod free of fugitive petroleum which typically adheres to the polish rod as it moves in and out of the well.
There are several, widely recognized, problems with stuffing boxes, however, which remain relatively constant despite numerous efforts to cure them. Specifically, the packing, or stuffing, tends to wear as the polish rod reciprocates. Because of the inherent need for the stuffing of packing to be flexible, there is a tendency for it to take a set, and even experience some shrinkage due to temperature changes, and under conditions where the well remains dormant for a period of time.
Finally, a problem inherent in pump design and construction, is a misalignment of the polish to sucker rod, string, or even slight bends or waves in the string, either one or both of which results in a slight, but universally devastating lateral movement of the sucker rod at the stuffing box which results in leakage of petroleum crude out of the top of the stuffing box and onto the adjacent land.
Virtually since pumping of subsurface wells began, a little petroleum on the ground around a stuffing box was of no particular concern. The stuffing or packing was periodically changed, but if the frequency of change was insufficient to prevent spills, no one seemed to care.
With growing environmental concerns came governmental organizations such as the Environmental Protection Agency. The growth and expansion of that agency's overview of petroleum production was spawned, in part, by a concern for petroleum spillage around well heads, and with it tightened restrictions, complete with significant fines for violations, for failure to hold such leakage in check. Accordingly, an objective of the present invention is to provide oil producers with a device which is capable of catching and accumulating such fugitive petroleum spillage, so as to permit inexpensive, yet efficient compliance with applicable EPA standards, while at the same time effectively eliminating losses due to spillage.
Another objective of the present invention, of course, is to provide apparatus which is capable of adapting to and overcoming stuffing box problems, including, but not limited to, misalignment, and/or curvature in the polish rod.